1. Field of the Invention
The present invention relates to a device and a method for detecting an approaching vehicle in a blind spot.
2. Description of the Related Art
There has been increasing use of assistance systems in modern automotive engineering; in particular, blind spot monitoring systems (side view assist, SVA) are known. These side view assist systems are capable of supporting the driver of a vehicle in a lane change or in backing out of a parking space. These systems are therefore capable of recognizing approaching vehicles and/or obstacles in a blind spot range. The driver of a vehicle equipped with such a side view assist system is then warned when an object is detected in the blind spot range. Side view assist systems have sensor systems for detecting other vehicles in a side lane and obstacles in the blind spot, these sensor systems generally being equipped with ultrasonic sensors.
One such system is known, for example, from published German patent application document DE 10 2006 037 591 A1, which has four ultrasonic sensors (so-called SVA ultrasonic sensors, where SVA stands for “side view assist”) mounted on the side of the vehicle for detecting a moving object in a blind spot. These ultrasonic sensors function as transceiver units. These so-called SVA ultrasonic sensors emit a query signal to search for objects in the blind spot. If an object is located in the blind spot, the query signal is reflected by the object and at least partially sent back to the same sensor. However, false warnings and errors may occur when one vehicle equipped with a side view assist system passes another vehicle also equipped with a side view assist system. The reason for the false warning is that the SVA ultrasonic sensors are unable to differentiate whether they are detecting the reflection of their own transmitted pulse from the query signal or a signal from a different ultrasonic source. This happens in particular since the query signals are not usually encoded by the corresponding vehicles and thus cannot be differentiated from one another.